Anti-cancer utility of HCG vaccines

ABSTRACT

This invention relates to a method of combatting cancer which cancer releases chorionic gonadotropin or a subunit thereof present in a mammal which method comprises administering to said animal an anti-cancer effective amount of a birth-control vaccine or an antibody to said chorionic gonadotropin or subunit thereof. Birth-control vaccines which are polyvalent vaccines and birth-control vaccines which employ recombinant organisms incorporating sequences coding for reproductive hormones are of particular interest as well as polyclonal and monoclonal antibodies to the chorionic gonadotropin.

BACKGROUND OF THE INVENTION

Human chorionic gonadotropin (hCG) is normally made by the trophoblastas an early hormonal signal of pregnancy. Its inactivation bybio-effective antibodies leads to the prevention of pregnancy. One ofus, Talwar, has been involved in the development of two types of birthcontrol vaccines, which induce the formation of antibodies competent toinactivate the bioactivity of hCG and thus control fertility. We havenow found an additional use of such vaccines and the antibodiesgenerated by them in prevention and cure of cancers secreting hCG. hCGand/or its α or β subunits are observed to be made by a number ofcancers as ectopic products. Our recent studies on one is such cancer,e.g. the human lung cancer, demonstrate that hCG and/or its subunitsmade by the human lung cancer cells act as autocrine growth promotersfor the tumour cells. Furthermore, antibodies inactivating the hormoneor its subunits arrest the growth of tumour cells in soft agar as alsoon progression of implanted tumour in nude mice in vivo. In cases inwhich antibodies are given to the animal prior to the implantation ofthe human lung cancer, the tumour fails to grow. The effect is dosedependent. When the antibodies are given to nude mice in which thetumour has previously grown, the antibodies cause necrosis of thetumour. These examples demonstrate the utility of the antibodies and/orthe vaccines generating such antibodies, to cure as well as prevent hCGsecreting tumours.

The birth control vaccine may, for example, be a vaccine of the typedisclosed in U.S. Pat. No. 4,780,312 issued 25 Oct. 1988 (inventor: G.P. Talwar). Another type of birth-control vaccine with this utility asan anti-cancer agent is a recombinant birth-control vaccine of the typedisclosed in WO 91/05049 (inventors: G. P. Talwar et al).

Rivera et al in J. Cell Biol. 108: 2423-2434 (1989) showed that a clonalstrain of human lung tumour cells which secrete large amounts of alphaand lower levels of beta subunits of human chorionic gonadotropin (hCG)in culture lose characteristics associated with tumorigenic potential(anchorage-independent growth) when in the presence of anti-alpha-hCGantibody. This effect could be partially reversed by adding alpha-hCG tothe medium.

The work of Rivera et al (op. cit.) shows that there is a need todevelop a vaccine which is compatible with the immune system of atumour-containing animal and indeed induces the immune system of theanimal to produce antibodies to the tumour.

Various Ohio State University patents to Stevens (e.g. U.S. Pat. No.4,767,842) disclose the use of a beta-hCG/tetanus toxoid modifiedpeptide (as described in U.S. Pat. No. 4,161,519 to Talwar) as ananti-cancer agent. In U.S. Pat. No. 4,767,842 examples XXXIV and XXXVIto XXXVIII relate to this utility. Some or all of the same examples arealso disclosed in other patents related to U.S. Pat. No. 4,767,842. Inall Stevens' examples the animals were immunized before exposure tocancer cells and therefore relate to the use of such antigens in theprevention rather than the cure of cancer. Stevens does not show the useof such an antigen in the cure of an already existing cancer.

Talwar (U.S. Pat. No. 4,780,312) and Talwar et al (WO 91/05049) haveworked to present a reproductive hormone to the immune system of afemale mammal in such a way that the immune system of the female mammalis stimulated to produce antibodies to the reproductive hormone therebydisrupting conception and providing a means of birth control. In acollaborative work from Dr. Biswas's laboratory and Dr. Talwar'slaboratory it has been reported that human lung cancer cells in culturewhich produce the alpha subunit of hCG induced tumours in female athymicmice. These tumours in athymic mice undergo necrotic degenerationfollowing local or intraperitoneal administration of an alpha specificantibody. The alpha hCG specific antibody did not affect the growth oftumours produced by human tumour cells which do not produce alpha-hCG.It is also demonstrated that withdrawal of the antibody treatment led tothe regeneration of tumours.

These observations predict that active production of antitumorigenicspecific antibodies such as alpha hCG in the tumour-bearing animals as aresult of active stimulation by a vaccine, specifically a birth-controlvaccine of the type discussed above. This overcomes the problem ofrenewed tumorigenesis when antibody treatment is discontinued and alsoproblems which may arise, when antibody treatment is employed, ofantibodies to the treatment antibodies being produced. The invention isespecially useful in controlling cancers which are dependent for theirgrowth and expansion on such molecules as reproductive hormones whichthe cancer itself often produces. By means of the invention a positivefeed-back loop which promotes cancer growth can be interrupted.

SUMMARY OF THE INVENTION

In one aspect this invention provides a method of combatting a cancer ina male or female mammal which cancer releases chorionic gonadotropin ora subunit thereof which method comprises administering to said mammal ananti-cancer effective amount of an antibody a birth-control vaccine tosaid chorionic gonadotropin or subunit thereof.

In another aspect this invention provides a commercial packagecomprising an anti-cancer effective amount of a birth-control vaccine orantibody to chorionic gonadotropin or subunit thereof together withinstructions for use of said birth-control vaccine or antibody as ananti-cancer agent in a male or female mammal.

The following are various preferred features of the invention.

In a preferred embodiment the vaccine or antibody is administered to amammal which already has cancer (this is curative rather thanpreventative).

In methods and uses of the invention if an antibody is used in passiveimmunization, the antibody may be monoclonal or polyclonal. In apreferred embodiment the antibody is an anti-alpha-hCG antibody.

In methods and uses of the invention the cancer releases a first peptideof a reproductive hormone and in "active" immunization the vaccineinduces antibody production, said antibody specifically binding to saidpeptide. In a further preferred feature the peptide is selected fromalpha and beta subunits of chorionic gonadotropin. The peptide of thereproductive hormones is preferably a peptide of a human reproductivehormone.

The vaccine can be monovalent or polyvalent. When polyvalent preferablythe vaccine comprises at least two hormone antigens of the reproductivesystem at least one of which is chorionic gonadotropin or a subunitthereof and at least one subject-compatible carrier, said polyvalentvaccine being selected from the group consisting of: (i) a compositeconjugate of at least two separate antigens linked to the same carriermoiety, (ii) a mixture of conjugates of at least two separate antigenseach separately linked to at least one carrier, (iii) an annealedcomposite of at least two separate antigens which are β subunit of hCGand an β subunit of hCG; conjugated to a carrier, and (iv) a mixture ofat least two of (i) to (iii).

Alternatively the polyvalent vaccine comprises at least two antigens ofthe reproductive system, a first being from a preparation of a β subunitof hCG and a second being a preparation of an α subunit of hCG and atleast one subject-compatible carrier, said polyvalent vaccine beingselected from the group consisting of: (i) a composite conjugate of atleast two separate antigens linked to the same carrier moiety, (ii) amixture of conjugates of at least two separate antigens each separatelylinked to at least one carrier, (iii) an annealed composite of at leasttwo separate antigens which are a β subunit of hCG and an α subunit ofhCG; conjugated to a carrier, and (iv) a mixture of at least two of (i)to (iii).

In particularly preferred embodiments more than one (especially two)subject-compatible carrier is present. Also preferably at least twoseparate antigens are hormonal subunits (e.g. alpha or beta-humanchorionic gonadotropin).

The subject compatible carrier preferably is one or more membersselected from the group consisting of tetanus toxoid, cholera toxinB-chain, hepatitis B surface protein, a malarial protein, diphtheriatoxoid and sporozoite coat protein of P. falciparum. Especiallypreferred are tetanus toxoid or cholera toxin B-chain.

The polyvalent vaccine may be mixed with an adjuvant selected from thegroup consisting of alum, detoxified sodium phthalyl derivative ofsalmonella lipopolysaccharide (SPLPS) and6-o-dipalmitoyl-glycerylsuccinyl (MDP).

In another embodiment the birth-control vaccine comprises a recombinantvirus incorporating in a non-essential part of the virus genome aheterologous nucleotide sequence capable of expressing a peptide of achorionic gonadotropin or an immunologically stimulatory fragmentthereof which peptide or fragment thereof has an epitope in common withsaid gonadotropin released by said cancer.

In a preferred feature a first sequence codes for a chorionicgonadotropin or active fragment thereof in reading frame alignment witha second sequence coding for at least part of a transmembrane anchorsequence of a Vesicular Stomatitis Virus Glycoprotein gene.

In a further preferred feature the nucleotide sequence comprises a firstsequence coding for a chorionic gonadotropin or active fragment thereofin reading frame alignment with a second sequence coding for at leastpart of a transmembrane anchor sequence of a Rabies Glycoprotein gene.

Alternatively the nucleotide sequence codes for (A) a fused peptidecomprising a first sequence coding for an alpha or beta subunit of amammalian gonadotropin in reading frame alignment with a second sequencecoding for a peptide anchor sequence whereby said nucleotide sequence,when inserted into a virus, said virus subsequently used to infect ahost cell and the fused peptide subsequently expressed, said fusedpeptide is anchored to the host cell membrane, or (B) an alpha subunitof a mammalian gonadotropin inserted into a viral nucleotide sequence,said alpha subunit of said mammalian gonadotropin being capable ofannealing to said membrane anchored peptide on co-expression of saidalpha subunit of said mammalian gonadotropin along with the membraneanchored peptide in the same host cell.

Such a nucleotide sequence (A) may comprise a first sequence coding foran alpha subunit of chorionic gonadotropin, or a beta subunit ofchorionic gonadotropin in reading frame alignment with a second sequencecoding for at least part of a Vesicular Stomatitis Virus Glycoproteingene.

Alternatively such a nucleotide sequence (A) may comprise a firstsequence coding for an alpha subunit of human chorionic gonadotropin, ora beta subunit of human chorionic gonadotropin in reading framealignment with a second sequence coding for a gene or gene fragment of ahepatitis B surface protein, or coding for at least part of a VesicularStomatitis Virus Glycoprotein gene. The second sequence may code for atransmembrane peptide or protein of at least part of a VesicularStomatitis Virus Glycoprotein gene.

In another preferred embodiment of the recombinant virus the firstsequence comprises the beta unit of human chorionic gonadotropin inreading frame alignment with a gene coding for the middle protein of ahepatitis B surface protein. An especially preferred embodiment of sucha recombinant virus is designated vSS4.

In another embodiment the birth-control vaccine comprises a recombinantvirus including nucleotide sequence (B) comprising an alpha subunit of amammalian gonadotropin inserted into a viral nucleotide sequence, saidalpha subunit of said mammalian gonadotropin being capable of annealingto said membrane anchored peptide on co-expression of said alpha subunitof said mammalian gonadotropin along with the membrane anchored peptidein the same cell.

In a further embodiment the birth control vaccine additionally iscapable of raising an antibody to at least one protein or peptideunassociated with the mammalian reproductive system. The protein orpeptide unassociated with the mammalian reproductive system may be ahepatitis B surface protein or fragment thereof.

In a further embodiment the virus comprises a recombinant avipox virusincorporating a heterologous gene sequence coding for a human chorionicgonadotropin or active fragment thereof. The heterologous sequence maycode, for example, for the alpha unit of human chorionic gonadotropin.

In another embodiment the virus comprises a recombinant avian poxviruscomprising a nucleotide sequence coding for a chorionic gonadotropinpeptide in reading frame alignment with an avian poxvirus nucleotide,said recombinant poxvirus being capable of expressing said peptide andstimulating an antibody response thereto when a mammal is inoculatedwith said recombinant poxvirus.

In a preferred embodiment the cancer generates a peptide of areproductive hormone and said vaccine comprises a recombinant virusincorporating a heterologous gene sequence coding for said peptide ofsaid reproductive hormone or an active fragment thereof.

DESCRIPTION OF THE INVENTION

Epidemiological surveys indicate that human lung cancers are oftenassociated with ectopic synthesis of hormones, predominantly humanchorionic gonadotropin (hCG). Increased circulating levels of hCG andits subunits are often used as biochemical markers for malignancy, anddecreased levels of the hormone hCG are often used as markers forsuccessful surgery in human lung tumours. Under physiologicalconditions, hCG is synthesized during the early stages of pregnancy bytrophoblastic cells. The ectopic synthesis of the hormone by lungtumours is an inappropriate expression.

The role of ectopic synthesis of the alpha subunit of hCG in thetransformation process in a cultured cell line (ChaGo) has been examined(a list of hCG-producing lung tumour cell lines is included in Table 1by way of example and Table 2 lists references to ectopic hormoneproduction by tumours of human tissues). This cell line was derived froma human bronchiogenic squamous cell carcinoma (See Fashhan et al, Proc.Natl. Acad. Sci. USA 70: 1419-1422 (1973) and Rivera et al, op. cite).ChaGo cells synthesize and secrete both the alpha and beta subunits ofhCG. The clonal strain of ChaGo cells used by way of example producespredominantly large amounts of alpha hCG. Rivera et al (op. cit.), inaddition to reporting the anti-tumorigenic effect of anti-alpha-hCGantibody, also found that stimulation of a alpha-hCG synthesis by cyclicadenosine monophosphate in the ChaGo cells also stimulated cellproliferation and cell progression into the S phase. The results belowconfirm that alpha hCG acts as an autocrine growth factor and plays animportant role in the transformation by maintaining the cells in aconstantly proliferating state. Vaccines inducing the formation ofanti-hCG antibodies have been developed (Talwar and Talwar et al (op.cit.) and Talwar et al Proc. Natl. Acad. Sci. USA 73: 218-222 (1976) andare now undergoing phase I and phase II clinical trials as birth controlvaccines (Talwar et al Contraception 41: 301-316 (1990)). A similartherapeutic approach to birth control for treatment of cancers whichshow ectopic synthesis of such hormones is therefore now feasible.

Materials and Methods

Tissue Culture

ChaGo cells were grown in Ham's F-10 medium (GIBCO Laboratories, GrandIsland, N.Y.) supplemented with 10% fetal bovine serum at 370° C. in 95%air and 5% CO₂. The details of the soft-agar technique were described inRivera et al (op. cit.).

Anti-α-hCG Antibody

The α subunit of the human chorionic gonadotropin (α-hCG), at 100 μg/mLin saline, was mixed with equal amounts of complete Freund adjuvant, and2 mL of this mixture was administered intradermally to goats. The purityof the αhCG samples used for raising the antibody was verified by sodiumdodecyl sulfate-polyacrylamide gel electrophoresis. A single proteinband was observed with electrophoretic mobility comparable to that ofthe authentic α-hCG obtained from the Hormone Distribution Agency(National Institutes of Health, Bethesda, Md.). Booster injections, withthe same amount of antigen in incomplete Freund adjuvant, were giventhree times every 30 days after the primary injection. Animals were thenrested for 6 months and given booster injections again with the sameamount of antigen in incomplete Freund adjuvant. These goats were bledafter 12 days, and the antigen-binding capacity of the serum wastitrated by radioimmunoassay.

The specific batch of polyvalent antibodies used in this investigationhas the antigen-binding capacity of 1892 μg/mL. The serum was dilutedwith phosphate-buffered saline to obtain the desired concentrations foradministration to athymic mice. Control serum was obtained from the samegoat prior to immunization. This normal goat serum was also diluted tothe same degree and administered to the control animals.

Rivera et al (op. cit.) reported the inhibition of growth of ChaGo cellsin tissue culture and soft agar in the presence of anti-alpha-hCGantibody. These properties were confirmed in our new batch of antibody.

Tumour Induction in Athymic Mice

Female athymic mice (nu/nu mice, 3-4 weeks old) were obtained from theNational Cancer Institute Frederick Cancer Research and DevelopmentCenter (Frederick, Md.). These animals were housed in sterile cages,maintained on sterile food and water, and separated from other animals.Tumours were induced by the implantation of 1-2×10⁶ ChaGo cells underthe dorsal skin of the mice. The animals were examined routinely forpalpable tumour growth. Tumour growth was monitored by routinephotography. Tumours were induced in 95% of the animals in a predictedtime sequence by one implantation of the indicated number of ChaGocells.

Histology

Tumours at different stages of development were surgically removed fromtreated and control animals and a small fragment of each tumour wasfixed in 10% formalin. Paraffin sections of these tumour fragments werestained with hematoxylin and eosin, after which they were examined andphotographed under a phase-contract microscope at the magnificationsindicated in the legends to the figures.

Induction of Necrosis of ChaGo Cell-Induced Tumour in Athymic Mice byAnti-α-hCG

The influence of local administration of the anti-alpha-hCG antibody onthe growth of the ChaGo cell-induced (1×106) tumours was examined. Twoweeks after ChaGo cells were implanted, the tumour attained a workablesize. At that time 500 ng of anti-alpha-hCG antibody was administered tofive experimental animals on the same site, twice a week, under thetumour. Two control animals routinely received equivalent amounts ofnormal goat serum (0.5 ml). Growth of the tumours was then monitored andphotographed 2, 3 and 5 weeks after the first administration ofanti-alpha-hCG antibody-containing serum or the normal goat serum. Theexperiment was repeated three times with the same number of control andtreatment animals (making a total of 6 and 15 animals respectively). Allanimals showed similar patterns of tumour growth in the control groupsand the same degree of tumour necrosis in the treated groups.

When the anti-α-hCG antibody treatment was stopped, the genesis processresumed in all three experimental animals. In the absence of thespecific antibody, the residual cells proliferated, and the tumour-massprogressively regenerated from the residual tumour cells within 4 weeksafter the antibody treatment was discontinued. These results demonstratethat tumour necrosis was specifically induced by the α-hCG antibody inthe administered serum. The tumour cells were deprived of the autocrinegrowth factor alpha-hCG, presumably due to the formation of the complexwith antibody. Depriving the cells of alpha-hCG not only inhibitedtumour growth but also induced extensive tumour necrosis.

The process of active necrosis in the presence of anti-α-hCG antibodywas more evident from the histopathological examination of the treatedtumour tissue. The results demonstrated that the untreated tumour cellswere proliferating with high mitotic index. However, the histopathologyof the treated tumour showed increased cellular necrosis with longertreatment with the alpha-hCG antibody. After 5 weeks of anti-alpha-hCGantibody treatment, patches of tumour cells were surrounded by massivenecrotic tissue. Pinocytosis and extensive tumour cell damage wereobserved. These results demonstrate regression of ChaGo cell-inducedtumours by the local administration of anti-alpha-hCG antibody,presumably because the cells were deprived of the essential growthfactor produced by the cells themselves.

Inhibition of Growth of ChaGo Cell-Induced Tumour by SimultaneousAdministration of Anti-α-hCG Antibody

The results above show necrosis of tumour cells and regression oftumours by alpha-hCG antibody treatment. The results presented in thissection demonstrate a concentration-dependent inhibition of tumourgrowth and tumour induction in athymic mice in the presence ofanti-alpha-hCG antibody. The same number of ChaGo cells (1×10⁶)suspended in 0.5 mL of phosphate-buffered saline containing 50-500 ng ofanti-alpha-hCG antibody were transplanted under the dorsal skin ofathymic mice (three animals in each treatment group). The controlanimals (three animals) also received the same number of cells withequivalent amounts of normal goat serum. The antibody treatment wascontinued at the respective concentrations, administered twice a weeklocally at the site of tumour cell transplantation.

The results show the pattern of tumour growth in the absence and in thepresence of indicated amounts of antibody as recorded by photography atdifferent intervals (2 weeks after tumour cell transplantation, 4 weeks,6 weeks, 8 weeks, and 10 weeks). Tumours grew in the control animals inan unrestricted manner and attained the indicated size within 8 weeks.Histo-pathological examination of sections of the ChaGo cell-inducedtumours showed cell proliferation with a high mitotic index. No visiblenecrosis of the tumour cells was detected. Although the continuedtreatment with 50 and 100 ng of anti-alpha-hCG antibody did notsubstantially inhibit tumour growth, necrosis of tumour tissue wasevident. Treatment with 200 ng of anti-alpha-hCG antibody, on the otherhand, significantly inhibited tumour growth. At 500 ng there was nopalpable growth, even 10 weeks after transplantation of the tumour cellsin the presence of continuous antibody treatment.

Histopathological examination of tumour tissues treated with 500 ng ofanti-alpha-hCG antibody revealed partial necrosis. These resultsdemonstrate that tumour growth can be inhibited and completely preventedby depriving the cells of alpha-hCG by continuous exogenousadministration of the antibody. A similar pattern of tumour growthinhibition was observed following intraperitoneal administration ofanti-alpha-hCG antibody simultaneously with the transplantation of ChaGocells at the dorsal surface of the animals. Continued passiveimmunization twice a week with 500 and 1000 ng of anti-alpha-hCGantibody prevented tumour growth completely.

The specificity of the anti-alpha-hCG antibody effect on the ChaGocell-induced tumour was verified by examining the effect ofanti-alpha-hCG on the growth of tumours induced by two hCG-nonproducinghuman tumour cells in culture. Human cell lines A431 (epidermoidcarcinoma) and T24 (bladder carcinoma) induced tumours in athymic mice,but the growth of both of these two types of tumours was not affected byanti-alpha-hCG antibody treatment.

These results support a role for alpha-hCG in the in vivo genesis of ahormone-producing human lung tumour. They also demonstrate a reversal oftumour phenotypes by the specific antibody. The fact that the tumourgrowth inhibition and prevention were observed only with theanti-aloha-hCG antibody-containing serum, and not with the serumobtained from the same goat prior to immunization, strongly suggeststhat this effect is due to the specific antibody and not to some otheragents in the serum. The two sera are isotypically matched, except thatthe one obtained after immunization contained the specific antibody.

The results of the experiments on treatment withdrawal furthersubstantiate the specificity of the effect of administeredanti-alpha-hCG antibody. Removal of the anti-alpha-hCG antibody reversedthe tumour growth inhibitory effect, even in the presence of normal goatserum. In the absence of the anti-alpha-hCG antibody the tumour grewback.

The results obtained provide a basis for the therapeutic treatment ofhormone-producing cancers by use of vaccines against the hormonesproduced by the cancers. External monitoring of the progression orregression of the cancer can be used to adjust dosage and use frequencyto ensure control and, preferably, elimination of the cancer.

In administering such birth-control vaccines for the purpose ofcontrolling cancer it is suggested that the initial dose and frequencybe similar to that used for birth-control purposes in female mammals.Frequency and dose can then be adjusted afterwards according to theresponse of the cancer and the comfort of the patient. As survivalrather than reproductive status of the patient is important dose anddose frequency can be adjusted accordingly.

In U.S. Pat. No. 4,780,312 200-300 g rats were inoculated with 10 μg ofconjugated gonadotropin and bonnet monkeys inoculated with 50 μg ofconjugated LH. Dose ranges may be 0.1 μg to 1000 μg per kg body weight,preferably 1 μg to 100 μg per kg body weight, particularly about 3 to 70μg per kg body weight.

In the case of recombinant virus vaccines doses of such virus whichwould lead to similar concentrations of conjugated birth-control hormoneare suggested. The required dose will, of course, vary widely from virusto virus and has to be determined empirically.

The use of vaccines is an "active" immunization approach which inducethe formation of antibodies in the body of the recipient. Dose,therefore, is related to the ability of the dose to raise antibodies.

The use of antibodies is a "passive" immunization approach. The dose ofsuch antibodies depends upon tumour load.

                  TABLE 1                                                         ______________________________________                                        Name         HCG Production                                                                             Source & Reference                                  ______________________________________                                        A. Squamous Cell Carcinoma                                                     1.   ChaGo C1   aHCG and bHCG                                                                              Tashjian                                                                              (8)                                      2.   ChaGo C5*  aHCG and bHCG                                                                              Tashjian                                                                              (8)                                      3.   ChaGo C10  bHCG and aHCG                                                                              Tashjian                                                                              (8)                                      4.   ChaGo K1   aHCG         ATCC    (8)                                      5.   EPLC-32M1  aHCG         Gazdar  (4)                                      6.   EPLC-65H   aHCG and bHCG                                                                              Gazdar  (4)                                      7.   NCI-H520   aHCG and bHCG                                                                              ATCC    (4)                                      8.   U1752      bHCG         Gazdar  (4)                                      9.   A549       aHCG and bHCG                                                                              ATCC    (4)                                     B. Adenocarcinoma                                                             10.   NCI-H23    aHCG and bHCG                                                                              Gazdar  (4)                                     11.   NCI-H358   aHCG and bHCG                                                                              Gazdar  (4)                                     12.   NCI-H650   aHCG and bHCG                                                                              Gazdar  (4)                                     13.   NCI-H752   aHCG         Gazdar  (4)                                     14.   NCI-H820   aHCG         Gazdar  (4)                                     C. Large Cell Carcinoma                                                       15.   LCLC-103H  aHCG and bHCG                                                                              Gazdar  (4)                                     D. Adenosquamous Carcinoma                                                    16.   NCI-H125   bHCG         Gazdar  (4)                                     17.   NCI-H596   aHCG         ATCC    (4)                                     E. Non-Small-Cell Carcinoma with Neuroendocrine Markers                       18.   NCI-H460   aHCG         ATCC    (4)                                     19.   NCI-H810   bHCG         Gazdar  (4)                                     F. Small-Cell Carcinoma                                                       20.   NCI-H679   aHCG and bHCG                                                                              Gazdar  (4)                                     21.   NCI-H720   bHCG         Gazdar  (4)                                     22.   NCI-H727   aHCG and bHCG                                                                              Gazdar  (4)                                     23.   SCLC-16HC  aHCG         Gazdar  (4)                                     24.   NCI-H678   bHCG         Gazdar  (4)                                     25.   NCI-H841   aHCG and bHCG                                                                              Gazdar  (4)                                     26.   DMS-79     aHCG         Gazdar  (4)                                     G. Extrapulmonary Small-Cell Carcinoma                                        27    NCI-H510   aHCG         Gazdar  (4)                                     ______________________________________                                         *Our preliminary observations are made from the experiments with this cel     line.                                                                    

                  TABLE 2                                                         ______________________________________                                        Ectopic Hormone Production by Tumors of Human Tissues                         Ectopic Hormone                                                                          Tumor Tissues References                                           ______________________________________                                        HCG        Lung          Tashjian et al., 1973                                HCG        Lung          Barrial & Zapata, 1982                               HCG        Lung          Dempo et al., 1981                                   HCG        Lung          Wilson et al., 1981                                  HCG        Lung          Tanimura, 1985                                       HCG        Lung          Hyderman, 1985                                       HCG        Bladder       Shah et al., 1986                                    HCG        Sweat gland of vulva                                                                        Fukuma et al., 1986                                  HCG        Testes        Jibiki et al., 1985                                  HCG        Breast        Lee et al., 1985                                     HCG        Epidermis     Nagelberg et al., 1985                               HCG        Testes        Bates & Longo, 1985                                  HCG        Bladder       Rodenburg et al., 1985                               HCG        Gastric mucosa                                                                              Manabe et al., 1985                                  HCG        Bladder       Yamase et al., 1985                                  HCG        Hydatiform mole                                                                             Romero et al., 1985                                  HCG        Testes        Tseng et al., 1985                                   HCG        Testes        Moriyama et al., 1985                                HCG        Gastric mucosa                                                                              Yonemura et al., 1985                                HCG        Hydatiform mole                                                                             Imamichi, 1985                                       HCG        Gastric mucosa                                                                              Ohyama et al., 1985                                  HCG        Genital tract Norman et al., 1985                                  HCG        Genital tract Bhattacharya, 1985                                   HCG        Liver         Nakagawara et al., 1985                              HCG        Colon         Hainsworth et al., 1985                              HCG        Testes        Hustin et al., 1985                                  HCG        Testes        Boewer et al., 1985                                  HCG        Colon         Metz et al., 1985                                    HCG        Adrenal gland Maeyama et al., 1985                                 HCG        Epidermis     Nagelberg et al., 1985                               HCG        Thyroid       Wurzel et al., 1984                                  HCG        Ovary         Kapp et al., 1985                                    HCG        Testes        de Bruijin et al., 1985                              HCG        Testes        Alm et al., 1984                                     HCG        Uterus        Mukher et al., 1984                                  HCG        Ovary         Brunstein et al., 1978                               ACTH       Thymus        Lowry et al., 1976                                   ACTH       Liver         Himsworth et al., 1977                               ACTH       Lung          Bertanga et al., 1978                                ACTH       Lung          Holander et al., 1982                                ACTH       Lung          Davis & Mary, 1982                                   AFP        Testes        Jibiki et al., 1985                                  AFP        Testes        Bates & Longo, 1985                                  AFP        Liver         Nakawara et al., 1985                                hPL        Breast        Sheth et al., 1977                                   PTH        Epidermis     Minne et al., 1978                                   hGH        Ovary, Breast & Long                                                                        Kagaowicz et al., 1979                               ______________________________________                                    

We claim:
 1. A method of treating a tumor in a mammal, cells of whichtumor release a polypeptide selected from the group consisting ofchorionic gonadotropin and a subunit thereof comprising: administeringto said mammal having said tumor an effective amount of anti-alpha-hCGantibody or a birth-control vaccine comprising an alpha subunit ofchorionic gonadotropin to induce necrosis of rumor cells and therebyregression of said tumor.
 2. A method according to claim 1 wherein saidvaccine further comprises a beta subunit of chorionic gonadotropin.
 3. Amethod according to claim 2 wherein said chorionic gonadotropin is ahuman chorionic gonadotropin.
 4. A method according to claim 1 whereinsaid vaccine is monovalent.
 5. A method according to claim 1 whereinsaid vaccine is polyvalent.
 6. A method according to claim 5 whereinsaid polyvalent vaccine comprises at least two hormone antigens of thereproductive system one of which said hormone antigens is said alphasubunit of chorionic gonadotropin and at least one subject-compatiblecarrier, said polyvalent vaccine being selected from the groupconsisting of:(i) a composite conjugate of at least two separate hormoneantigens linked to the same carrier moiety, (ii) a mixture of conjugatesof at least two separate hormone antigens each separately linked to atleast one carrier, (iii) an annealed composite of at least two separatehormone antigens one of which is said alpha subunit of chorionicgonadotropin and the second of which is a beta subunit of chorionicgonadotropin, conjugated to a carrier, and (iv) a mixture of at leasttwo of (i) to (iii).
 7. A method according to claim 5 wherein saidpolyvalent vaccine comprises at least two hormone antigens of thereproductive system, the first being beta subunit of chorionicgonadotropin and the second being said alpha subunit of chorionicgonadotropin and at least one subject-compatible carrier, saidpolyvalent vaccine being selected from the group consisting of:(i) acomposite conjugate of at least two separate of the said two hormoneantigens linked to the same carrier moiety, (ii) a mixture of conjugatesof at least two separate of the said two hormone antigens eachseparately linked to at least one carrier, (iii) an annealed compositeof at least two of the said separate hormone antigens conjugated to acarrier, and (iv) a mixture of at least two of (i) to (iii).
 8. A methodaccording to claim 6 wherein in said polyvalent vaccine more than onesubject-compatible carrier is present.
 9. A method according to claim 6wherein in said polyvalent vaccine both of the two separate antigens arehormonal subunits.
 10. A method according to claim 6 wherein in saidpolyvalent vaccine two subject-compatible carriers are present.
 11. Amethod according to claim 6 wherein in said polyvalent vaccine saidsubject compatible carrier is one or more members selected from thegroup consisting of tetanus toxoid, cholera toxin B-chain, hepatitis Bsurface protein, a malarial protein, diphtheria toxoid and sporozoitecoat protein of P. falciparum.
 12. A method according to claim 6 whereinsaid carrier is tetanus toxoid or cholera toxin B-chain.
 13. A methodaccording to claim 6 wherein said polyvalent vaccine is mixed with anadjuvant selected from the group consisting of alum, detoxified sodiumphthalyl derivative of salmonella lipopolysaccharide (SPLPS) and6-o-dipalmitoyl-glyceryl-succinyl (MDP).